Nephropathic cystinosis is an inherited disease with multiple clinical manifestations including Fanconi's syndrome and progressive kidney failure. Within the past decade, cysteamine and phosphocysteamine were developed as orphan drugs. These compounds have now been found to be effective in reducing the rate of progression of cystinosis. However, multiple daily doses of medication and regular monitoring of white blood cell cystine levels are essential to optimal outcomes. Processing of blood specimens for white blood cell cystine levels is very cumbersome and time consuming. This to the extent that GCRC participation and assistance with obtaining reliable white blood cell cystine levels has been necessary. A single patient has been enrolled in this compassionate use protocol. At present, there are no plans for enrollment of further subjects. The patient treated has had an impressive reduction in white blood cell cystine levels, and now has a white blood cell cystine level that is within the normal heterozygote range. Thus, we have every expectation that the medication will be of clear benefit to her. She has tolerated the medication well and without any adverse reactions.